Gophersnake - Pituophis catenifer
(see State Rank Reason below)
State Rank Reason (see State Rank above)
Species is relatively common within suitable habitat and widely distributed across portions of the state
- Details on Status Ranking and Review
ScoreG - 200,000-2,500,000 km squared (about 80,000-1,000,000 square miles)
Comment380,531 square Kilometers from Natural Heritage Program range maps
ScoreE - Relatively Stable (±25% change)
CommentHabitat is likely stable within +/- 25% since European settlement, but persecution by people may drive local extirpations of this species
ScoreU - Unknown. Short-term trend in population, range, area occupied, and number and condition of occurrences unknown.
CommentNo data on trends available
ScoreH - Unthreatened. Threats if any, when considered in comparison with natural fluctuation and change, are minimal or very localized, not leading to significant loss or degradation of populations or area even over a few decades’ time. (Severity, scope, and/or immediacy of threat considered Insignificant.)
CommentUnknown, but mortality due to basking on roads both directly from vehicle collisions and persecution due to increased visibility may contribute to higher mortality of reproductive aged individuals.
ScoreB - Moderately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance over a period of several years (on the order of 5-20 years or 2-5 generations); or species has moderate dispersal capability such that extirpated populations generally become reestablished through natural recolonization (unaided by humans).
CommentModerately Vulnerable. Species exhibits moderate age of maturity, frequency of reproduction, and/or fecundity such that populations generally tend to recover from decreases in abundance within 5-20 years or 2-5 generations. Species has good dispersal ca
ScoreC - Moderate. Generalist. Broad-scale or diverse (general) habitat(s) or other abiotic and/or biotic factors are used or required by the species but some key requirements are scarce in the generalized range of the species within the area of interest.
CommentWithin its range this species is associated with a wide range of habitats
Raw Conservation Status Score
3.5 + 0 (geographic distribution) + 0 (environmental specificity) + 0 (long-term trend) + 1 (threats) = 4.5
The Gophersnake or Bullsnake is Montana’s largest snake and can reach a length of 7 feet; most range in length from 3 to 5 feet. It can be readily identified by a series of large black to brown blotches that run down the back, and another series along the sides. The blotches, which are set on a yellow background, become more widely spaced toward the tail. The dorsal scales are keeled (have a ridge running down the center). A black band can usually be seen on the head in front of and extending below the eyes. The belly is yellow to white, often spotted with black. Dorsal coloration varies geographically, but in most areas has numerous dark blotches on a cream or yellowish background.
Differs from other similar species by having the following combination of characteristics: keeled scales, 4 prefrontals, and an undivided anal plate. Rat snakes (Elaphe) and kingsnakes (Lampropeltis), have only two prefrontal scales. Also, Elaphe has a divided anal plate. Whipsnakes (Masticophis), racers (Coluber), and indigo snakes (Drymarchon) have smooth body scales.
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Gophersnakes are associated with dry habitats, including open pine forests. They feed on rodents, rabbits, ground-dwelling birds, and to a lesser extent lizards. They sometimes hiss and vibrate their tail when alarmed, producing a sound similar to that of rattlesnakes. They occasionally climb trees. Females lay 2 to 24 eggs in summer. North-central MT: of 12 records, 9 in river valley, 1 in coulee, 2 on prairie (Mosimann and Rabb 1952). One found in rocky sagebrush area north of Arlee, MT (Franz 1971). Common in southeast Alberta in brushy coulees, sage flats, and along roads (Lewin 1963).
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
- Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: mtnhp.org/requests
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
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- Commonly Associated with these Ecological Systems
Forest and Woodland Systems
Human Land Use
Recently Disturbed or Modified
Shrubland, Steppe and Savanna Systems
Sparse and Barren Systems
Wetland and Riparian Systems
- Occasionally Associated with these Ecological Systems
Forest and Woodland Systems
Human Land Use
Recently Disturbed or Modified
Wetland and Riparian Systems
Active forager by searching.
Overwinter survival in northern UT greater than 88% (adults), 25% (juveniles) (Parker and Brown 1980). Densities of 1.3 snakes/ha reported for ID (Nussbaum et al. 1983).
Mate in late May to June; lay eggs late June to July; hatch late August to September (Hammerson 1982). Clutch size averages 12.4 (Fitch 1970). Hatching success in northern Utah was 92% (Parker and Brown 1980).
- Literature Cited AboveLegend: View Online Publication
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- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
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- Additional Sources of Information Related to "Reptiles"